This invention relates generally to transport or conveyor devices for supporting and carrying production parts through production processes. More specifically, this invention relates to an improved transport belt for gripping and carrying relatively thin and/or fragile parts such as electronic components during production processes, for example, including electroplating steps and the like.
A variety of transport and/or conveyor devices are well known for use in automated or semi-automated transfer of production items between successive processing stations. For example, in many such devices, a transport belt is provided with gripping components for grasping and supporting production items as the belt is indexed to carry the production items through various processing steps. In one common form, the gripping components comprise clamp fingers connected to the transport belt and urged by springs toward engagement with each other thereby providing clamping forces to grip and hold the production parts. See, for example, U.S. Pat. No. 2,919,705. The belt is conveyed by suitable drive means past a loading station having means for opening the clamp fingers and inserting production parts therebetween, and an unloading station with means for removing processed parts from the clamp fingers.
In some production applications, simplified transport belt devices have been proposed including clamp or spring finger components formed integrally with a transport belt, thereby eliminating the need for separately mounted clamp finger components and associated springs. Such integral or unitary transport belt constructions have been formed from an elongated web of suitable spring material, such as stainless steel or the like, to provide a relatively cost-efficient belt device useful in gripping and carrying relatively small or lightweight production parts, particularly such as electronic components as they are carried, for example, through a sequence of electroplating or other production process steps. See, for example, U.S. Pat. No. 4,534,843. However, previous unitary transport belt devices have utilized a succession of spring fingers bent in opposite directions to engage a production part alternately on opposite sides thereof. This arrangement results in the application of unbalanced gripping forces which can distort relatively lightweight, thin, or flexible production parts, such as thin conductive contact components, thin circuit boards, foil elements, and the like.
There exists, therefore, a significant need for an improved transport belt including unitary gripping means for grasping and carrying production parts without applying unbalanced, potentially distorting forces to the production parts. The present invention fulfills these needs and provides further related advantages.